/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.tomcat.util.modeler.modules;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URL;
import java.util.List;

import javax.management.ObjectName;

import org.apache.tomcat.util.modeler.Registry;

/**
 * Source for descriptor data. More sources can be added.
 * 
 */
public class ModelerSource {
	protected Object source;
	protected String location;

	/**
	 * Load data, returns a list of items.
	 * 
	 * @param registry
	 * @param location
	 * @param type
	 * @param source
	 *            Introspected object or some other source
	 * @throws Exception
	 */
	public List loadDescriptors(Registry registry, String location,
			String type, Object source) throws Exception {
		// TODO
		return null;
	}

	/**
	 * Callback from the BaseMBean to notify that an attribute has changed. Can
	 * be used to implement persistence.
	 * 
	 * @param oname
	 * @param name
	 * @param value
	 */
	public void updateField(ObjectName oname, String name, Object value) {
		// nothing by default
	}

	public void store() {
		// nothing
	}

	protected InputStream getInputStream() throws IOException {
		if (source instanceof URL) {
			URL url = (URL) source;
			location = url.toString();
			return url.openStream();
		} else if (source instanceof File) {
			location = ((File) source).getAbsolutePath();
			return new FileInputStream((File) source);
		} else if (source instanceof String) {
			location = (String) source;
			return new FileInputStream((String) source);
		} else if (source instanceof InputStream) {
			return (InputStream) source;
		}
		return null;
	}

}
